This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Patients with alcohol use disorders are often cared for in the intensive care unit (ICU). We estimate that close to half of the patients we care for in our ICU have alcohol use disorders. One of the reasons that patients with alcohol use disorders are frequently cared for in our ICU is because patients with alcohol use disorders are at higher risk of developing infections. The medical term for infections is sepsis. When an infection develops, patients with alcohol use disorders tend to get more severely ill compared to patients who do not have alcohol use disorders. Patients with alcohol use disorders are also at higher risk of dying when they develop severe infections. The purpose of this study is to determine why patients with alcohol use disorders become more severely ill when they develop infections. There are a number of reasons why this is possible. One reason is that a hormone called cortisol is higher in individuals with alcohol use disorders (who do not have infections). This hormone is also higher in patients who are at increased risk of dying from severe infections. One of the aims of this study is to see if cortisol levels are higher in patients with alcohol use disorders compared to those who do not have alcohol use disorders. Another reason why patients with alcohol use disorders are at increased risk of developing infections is because their immune system is not functioning properly. A second aim of this study is to see if certain markers of immune function are different in patients with alcohol use disorders compared to patients without alcohol use disorders. We will measure these markers on blood that has already been drawn and is now located in the hospital laboratory. You will not have additional blood drawn if you choose to participate in this research study. Patients with alcohol use disorders are also more likely to become confused when they are in the ICU. This condition is called delirium. Delirium is marked by abrupt onset of altered level of consciousness, disorganized thinking, and inattention that changes over time. Delirium tremens is one form of delirium. About 80% of our ICU patients develop delirium, and many patients who do not have alcohol use disorders develop the disorder as well. Patients with alcohol use disorders who have high cortisol levels have a higher chance of developing delirium compared to patients with normal cortisol levels. A third aim of this study is to examine the relationship between delirium and cortisol in both patients with and without alcohol use disorders.